The present invention relates to an air-suspension system suitably used as a suspension system for vehicles, for example, automobiles.
A generally known air-suspension system has a damper body and a piston rod projecting from the upper end of the damper body. The piston rod is capable of extending and contracting. A roofed cylinder-shaped canister (i.e., a cylinder-shaped canister having a closed end) is provided at the projecting end of the piston rod. A bottomed cylinder-shaped air piston (i.e., a cylinder-shaped air piston having a closed end) is provided on the outer periphery of the damper body in opposing relation to the canister. A rubber tube is secured at both ends thereof to the canister and the air piston to define an air chamber therein.
In recent air-suspension systems, the canister and the air piston are partially formed of a resin material to achieve an improvement in assemble-ability and a reduction in the weight of the systems.
In such known air-suspension systems, the canister is fitted to a canister cap secured to the vehicle body, and the air piston is fitted to an air piston guide secured to the damper body. As the pressure in the air chamber increases, the canister tends to come off or separate from the canister cap, and the air piston also tends to come off or separate from the air piston guide. Therefore, it is necessary to provide coming-off preventing members or members to prevent this separation in the fit between the canister and the canister cap and in the fit between the air piston and the air piston guide. Consequently, the configurations of these elements become complicated, causing a reduction of productivity and an increase in the production cost.